What do you do if you have been dating your girlfriend for over 7 months and you love her deeply and then kiss another girl?

Keep your mouth shut and don't do it again. Please tell her..because if she finds out another way she will be hurt. at any rate don't do it again. Think about why u kissed another girl and get that resolved. She deserves to know and make her own decision about how she feels about it. IF ur love is true u will be able to get through this.